VITAMIN G (B2) 137 



Distribution of Vitamin G (B2) in Food Materials 



In the course of work demonstrating the multiple nature of the 

 vitamin B complex some indications of the distribution of vitamin G 

 (B2) have been given. It has been found in yeast, fresh or autoclaved, 

 in milk, lean meat, and green leaves. 



In studies of the relative vitamin G (Bo) content of foods Aykroyd 

 and Roscoe (1929) used as a basis of comparison the minimum amounts 

 of food materials which when incorporated into, or added to a vitamin 

 G-deficient basal diet, provide enough vitamin G (B2) to permit an 

 11- to 14-gram weekly increase of body-weight in the experimental rat. 

 From the work of our laboratory it appears that this rate of growth 

 requires about three times as much vitamin G as is required to main- 

 tain a rate of gain of about 3 grams per week, at which level our 

 quantitative comparisons are made. Thus the Aykroyd-Roscoe "units" 

 are about 3 times as large as the Bourquin units. In so far as possible 

 the vitamin G (B2) values of foodstuffs in the following text will be 

 expressed in one or the other of these terms. 



Cereals. — To furnish one Aykroyd-Roscoe unit, cereal products 

 formed a large part of the diet: whole English wheat, 50 per cent; 

 Manitoba wheat, whole grain, 30 to 50 per cent, embryo, bran or 

 pollard, 15 to 30 per cent, patent or household flour, 65 per cent; white 

 African maize, 50 per cent ; yellow South American maize, more than 

 50 per cent ; germ meal 30 to 60 per cent ; endosperm grits or Italian 

 polenta, more than 65 per cent (Aykroyd and Roscoe, 1929). Bourquin 

 (1930) reported 1.5 of her units of vitamin G per gram of ground 

 whole winter wheat. 



Maize, long associated with the occurrence of pellagra was reported 

 by Goldberger, Wheeler, Lillie and Rogers (1928) to contain little of 

 the black-tongue preventive factor ; wheat to contain somewhat more, 

 and extracted commercial wheat embryo at least twice as much. 



Legumes. — Thirty to 40 per cent of dried peas in the ration fur- 

 nished one Aykroyd-Roscoe unit (1929). Goldberger and his coworkers 

 found that cowpeas, while containing some of the black-tongue pre- 

 venting factor, perhaps half as much as did wheat germ, was a poor 

 preventive of black-tongue and pellagra (Goldberger and Wheeler, 

 1927a). Soy beans, fed in large amounts, showed the presence of black- 

 tongue preventive factor (1928). 



Yeast. — Dried yeast was reported by Aykroyd and Roscoe (1929) 

 to contain 5 to 10 Aykroyd-Roscoe units per gram; Quinn, Whalen 

 and Hartley (1930) found 10 to 15 Bourquin units per gram (5 



